Electrode structure for electric precipitators



July 16, 1940. FlESEL I 2,208,289

ELECTRODE STRUCTURE FOR ELECTRIC PRECIPITATORS Filed Dec. 26, 1939 if. t

' u I HERMANN F'IEsEL,

m M XECUTOE flnmwg Patented Julylfi, I a i I UNITED) STATES- 'YPATENT OFFICE ELECTRODE s'muo'maa FOB anaemic 1 rancm'mroas Hermann Fiesel, deceased, late of Frankfort-onthe-Main, Germany, by Hildegard A. S. Flescl, executor, Frankfort-on-therMain, Germany, as-

signor to Western Precipitation Corporation, Los Angeles, Calif., a corporation of California Application December 26, 1939, Serial No. 311,030

' In Germany March 26, 1938 i 7 Claims. (cuss-'1) The present invention is concerned generally tent which are not warped so much as to be unwith the art of electrically precipitating sususable. Because of the large amount of material pended particles from a stream of gas, and more" rejected in the manufacture of carbon plates,

, particularly with improvements in the constructhe costof acceptable flat sheet material is ung tion of non-discharging electrodes. The-procusually high.

es of precipitating suspended particles from These disadvantagesareovercome accordingto a stream of gas is accomplished by passing the yl n by building up t e o la gas stream through an electric charging field in ing electrode from a plurality of elongated, rodwhich coronadischargeis produced that causes shaped members. The rod-shaped members are no the suspended particles'in the gas stream to bearranged in layers with the members of each 10 come electrically charged, and then the charged layer spaced from one another and with the particles are moved toward and precipitated upon members of successivelayers laid at an angle, the surface of a non dischar'ging'collecting elecpreferably a r h n le, with resp to h trade as a result of the force exerted upon the other. As a result of spacing the members of in charge particles by an electric iield' which may chleyer an q l fllm d singularly be the charging field Just referred to or may be P0 8 he m mb rs of successiv l y r the a spatially separate electrostatic field. Appaj completed structure of severaliayers forms one or latus of various types in. which these operations more polygonal, preferably square, gas passages are carried out is generally referred to as an through which the stream ofgas with the suse m electrical precipitator. pended particl s can pass. ach of th gas n 2o In the foilo description, the term dissages being adapted to receive and surround an charge electrode" will be i'inder'stood to designate opposing electrode 'which may be either of the an electrode that facilitates corona, discharge discharge or non-discharging type. Ordinarily therefrom, because it has a configuration that 'the layers are horizontal and consequently the establishes a sufliciently high potential gradient gas passages are vertical. Also, the members are 25 at or near its surfaceto create a corona disadvantageously stacked on each other so that charge before there is a' disruptive discharge or each layer supports the layers above it. This consparkover. Conversely, the term"non-discharg: striiction is simple and economical to erect, as

ing electrode will be understoodto designate an well as being relatively inexpensive from the M electrode that minimizes or prevents corona disstandpoint of the cost of the materials. Howcharge therefrom because it has a configuration ever, it is within the scope of my invention to that establishes a sumciently lowfield concensupport individually each layer of members.

tration at or near the surface to suppress corona How the above obiects and advantages of my discharge at elevated potentials lower than the invention, as-well as other objects and advantages voltage required for disruptive discharge or not specifically mentioned, are attained will be 85 sparkover. For this reason, a non-discharging better understood by reference to the following electrode usually is one of extended surface area description and the annexed drawing, in which: that is substantially free from sharp corners or Fig. Us a fragmentary vertical section through other parts of sharp surf ace curvature at points a portion of a typicalelectrical precipitator illuswithin the electric field. tratlng a non-discharging electrode constructed 0 -Although in its broad aspect my invention h according to my invention; I 1

not limited to any special material or materials, Fig. 2 is a plan section on line 2-2 of Fig. 1;

it is intended particularly to be used with non- Fig. 3 is a fragmentary elevation and section metallic semi-conducting materials which may of several rod-shaped members illustrating a be cast or moulded into elongated, rod-shaped modification oi the inventlonin which the mem- 'members. One typical application in which the bets are provided with 1' present invention has marked advantages is in Fig. -4 .is a fragmentary elevation of a single the formation of non-discharging electrodes one of the members of Fig. 8;,

which are made of carbon in order to be resistant Fig. 5 is a fragmentary elevation and section to corrosion by acids and other substances. Carof several of the' rod-shapedmer'noers illustratban is amaterial used particularly in precipiing another modification of the invention in 7 tators designed for collection of acid fumes or which the members are provided with recesses; other tubes which. are particularly corrosive. Fig. 6 is a cross-section through the recessed However, it is very difilcult andexpensive to portion of a single member of Fig. 5;

form carbon into "sheets of sufllciently great ex- 7 isa fragmentary perspective view of "a 5 v single rod-shaped member of rectangular crosssection; and

Fig. 8 is a fragmentaryelevation and section of a hollow rod-shaped member,

There is indicated at iii in Figs. 1 and 2 a vertically extending gas flue or conduit which is rectangular, preferably square, in cross-section. The walls of flue l0 are'provided with ledges. iOa

which support the cribwork structure of the nondischarging electrode indicatedgenerally at I2.

The non-discharging electrode M2 is composedof I a plurality of rod-shaped members ll stacked vertically on one another ina series of horizontal layers. The lowermost or bottom layer of members ll rests directly upon ledges la. The

layer next above is placed directly upon the bottom layer with the members of one layer disposed at 'right angles with respect to the members of the other layer. The members of each vertically stacking aseries of such horizontal layer are parallel to one another and spaced from each other, the spacing in all layers preferably being the same as shown in Figs. 1 and 2. By

layers upon one another as shown in Fig. 1, there results from this arrangement a plurality of vertically extending gas passages or cells it, as indicated. in Fig. 2. Each of these gas passages is'a subdivision of the main flue Ill and'ls adapt ed to receive and surround a centrally positioned opposing electrode it, here shown as a discharge electrode comprising a length of wire of relatively small diameter stretched taut-by a weight on the lower end of the wire.

Although the opposing electrodes l8 in Figs. 1 and 2 are the discharge type, it will be understood that the invention is not limited to any particular type of electrode and that non-discharging electrodes may also be placed within gas passages it to oppose electrode I2.

Any desired material maybe used for .the rodshaped members i4, butit is contemplated that they will be made principally of carbon where.-

a corrosion resistant electrode is desired.

In the cribwork construction illustrated in Figs; 1 and 2, members II are solid cylindrical rods. If it'is desired to hold the rods againstlateral movement, as by rolling, as well as to facilitate vertical alignment of the members M in alternate layers, the individual member It may be recessed in any one ar a number of ways.

Some typical manners of recessing are illustrated in Figs. 3-7 inclusive; and in general it is preferred to recess the rods at theinends and at theintermediate points where the rods of successive layers cross over or engage each other ingorder to keep the members II in their proper positions and maintain the proper size and shape of the various gas passages l8.

Fig. 3 illustrates one manner of recessing the aligned members of alternate layers. Thus in] the construction of Fig. 1,' the distance between alternate layers is equalto the diameter of the intervening members :but in the construction acoaaea of Fig. 3 the spacing between alternate layers .is reduced by an amount equal to twice the depth of a notch".

In the event it is desired to substantially eliminate the spacing between vertically aligned members ll of alternate layers, this can be accomplished by providing the members with somewhat deeper notches 22 as indicated in Figs. 5 ,and 6. In this configuration of members it,

recesses 22 are provided vin all members both at their ends and also at the intermediate points where the rods of successive layers engage or cross "each other, recesses 22 having a depth equal to one-fourth thediameter of the member i4. Two diametrically opposite recesses 22 each of a depth equal to one-fourth the diameter leave a central portion of the member Hi of :8. thickness of one-half the diameter of the rod,

as indicated at Ila in Fig. 6. This portion lid is received in and fills the space created by two adjoining vertically aligned recesses 22 in the rods of alternate layers, as may be seen from Fig. 5. With thisconstruction, the members ill of alternate layers, being parallel to one anotherand vertically aligned, are in contact, or substantially so, throughout their entire length and the spacing between the rods is substantially eliminated. This type of construction not only increases the amount of electrode surfaceavailable in the non-discharging electrode It to op-v pose electrode l8, but also]. mewhat reduces turbulent flow since there is no opening through which the gas may flow fromfone'passage i6 to another. a

The construction of Figs. 5 and 6 may be considered asderived from the construction of Figs. 3 and 4. by deepening the recesses and placing recesses in all of the members l4. From-this discussion it willbe apparent to those skilled in the art that other sizes and arrangements of recesses may be used. Thus, all members 'may have recesses as at 22 but of a lesser depth, such as at 20; to hold the members in place but still leave spaces between them.

It is to be understood that the invention is in no waylimited to cylindrical rods for members M, although it is preferred to use members of j this shape in building up the electrode since sharp corners tending to produce corona discharge are eliminated. However, under some circumstances it may be entirely satisfactory to use rod-shaped members which are polygonal in outline, or

whichhave a periphery made up of both straight and curved lines. .As an example of a different P shape of member II which maybe used, there is illustrated in Fig. 'l a square rod-shaped member I db-which is provided with notches 24 on opposite faces, the notches being rectangular in outline and-adaptedto receive another square member I lb of the same shape as the one illustrated.

When recesses .24 have a depth equal to onefourth the linear'dimension of one sided the square member I 4b,.the vertically aligned square members of alternate layers rest one upon another and are held in proper alignment to maintain a substantially smooth, unbroken, vertical surface on the inside of each 61 gas passages IS.

The opposing electrode i2 then is much the same .as if formed of a continuous sheet at'each 'side of the passages l6, and substantially no detrimental eflects are encountered'from the-presence of the sharp corners on each of the square members Mb. Advantages -.of square members are that gas flow through' the passages I6 is. less turbulent, because thewalis-of the passages are 75 I smoother, and the bearing area oi th'e rods is, greatly increased so that larger loads can be carried without crushing.

From the foregoing it will be understood that the term rod-shaped, as applied to members ll,

includes various elongated members characterized by a relatively great longitudinal dimension and relatively small transverse dimensions. The cross-sectional outline may change; and also the members It may be hollow as well as solid. Way of example there'is shown in Fig. 8 atubular member M with an internal bore 26 extending throughout the length of the member. 7

Having described my invention and certain preferred embodiments thereof, it will be understood that various changes in the configuration and arrangement of the various parts may be made by those skilled in the art without departing from the spirit and scope of my invention; and consequently it is to be understood the foregoing description is illustrative oi, rather than limitative upon, the appended claims.

I claim:

1. A non-discharging electrode structure for use in an electric precipitator, comprising a plurality of cast rod-shaped members made ofnonmetallic material arranged in layers with the members of each layer spaced from each other and the members of successive layers angularly disposed to each other, and the rodshaped members being arranged to form a polygonal gas passage adapted to receive and surround an opposing electrode.

2. A non-discharging electrode structure for use in an electric precipitator, comprising a plurality of horizontally extending rod-shaped members stacked vertically on each other in horizontal layers with the members of each layer spaced from each other and the members of successive 40 layers angularly disposed to each other, and the Executor of the rod-shaped members being arranged toforma vertically extending polygonal gas passage adapted to receive and surround an'opposing electrode.

3. A non-discharging electrode structure for. use in an electric precipitator, comprising a plurality oi horizontally extending rod-shaped members stacked vertically on each other in horizontal layers with. the members of each layer spaced from each other'and the members of successive layers dis osedat right angles to each other, and the rod-s ped members being arranged to form a vertically extending rectangular gas passage adapted to receive and surround an opposing electrode.

4.1a non-discharging electrode structure for use in an electric precipitator, comprising a plurality'of rod-shaped members arranged in layers with the members of each layer spaced from each other and the members of successive layers disposed at right angles to each other, and the-rodshaped members being arranged to form a'plurality of rectangular gas passages each adapted to receive and surround an opposing electrode.

5.. A non-discharging electrode structure as set out in claim 2 in'which the members are provided with recesses that engage adjoining members and hold them against lateral displacement.

6. Anon-discharging electrode structure as set 

